Lopez, 38, is best known as the host of TV's "Extra" entertainment news program. He also was a cast member of the 1990s sitcom "Saved by the Bell."
Mazza, 28, is a dancer, who has appeared in the Broadway musicals "A Chorus Line" and "The Little Mermaid."
The couple are the parents of a 2-year-old daughter.
"We took a walk alone as the sun was setting," Lopez told UsMagazine.com of how he proposed to his girlfriend and how she accepted. "I told Courtney that I wanted the mother of my children to have their last name. She was silent at first from shock, then she leaped for joy and did a little jete."
"Besides our daughter's birth, this was the best moment of my life!" Mazza added.
Lopez and Mazza told the magazine they plan to marry in Mexico this year.
Celebrity Families of 2014 [PHOTOS]